The shell game that we play ... is technically called 'renormalization'. But no matter how clever the word, it is still what I would call a dippy process! Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics is mathematically self-consistent. It's surprising that the theory still hasn't been proved self-consistent one way or the other by now; I suspect that renormalization is not mathematically legitimate.
Richard P. FeynmanWhen the problem [quantum chromodynamics] is finally solved, it will all be by imagination. Then there will be some big thing about the great way it was done. But it's simple -it will all be by imagination, and persistence.
Richard P. FeynmanWhen you get as old as I am, you start to realize that you've told most of the good stuff you know to other people anyway.
Richard P. FeynmanIt is surprising that people do not believe that there is imagination in science. It is a very interesting kind of imagination, unlike that of the artist. The great difficulty is in trying to imagine something that you have never seen, that is consistent in every detail with what has already been seen, and that is different from what has been thought of; furthermore, it must be definite and not a vague proposition. That is indeed difficult.
Richard P. FeynmanYou know how it always is, every new idea, it takes a generation or two until it becomes obvious that there's no real problem. It has not yet become obvious to me that there's no real problem. I cannot define the real problem, therefore I suspect there's no real problem, but I'm not sure there's no real problem.
Richard P. Feynman